(a) Technical Field
The present invention relates to a system and method for improving the output performance of a battery of an environment-friendly vehicle or the like, and more particularly, to a system and method for controlling the cooling and/or heating of a battery, which is configured to control the temperature more reliably and precisely.
(b) Background Art
Some batteries are made in the form of one module using a plurality of cells each having a thin plate structure. A plurality of modules are typically connected in series to make up a battery pack, depending on the performance of a vehicle (i.e., how much power is required from the vehicle). These battery packs which include a plurality of modules are typically surrounded by a housing, a cover or the like to protect the modules from exterior elements.
When such a battery pack is charged or discharged via a chemical reaction, heat is generated within the cell. The charging or discharging power of the battery changes depending on the temperature of the cell. Thus, it is important that the temperature of the cell be maintained within a proper range so that the battery is operated with its internal temperature of between about 20° C. to 40° C., for example.
Accordingly, vehicles with high voltage battery, which especially generate a lot of heat, such as electric vehicles, should be provided with both a cooling system the high-voltage battery when the battery becomes too hot and a battery heating system to warm the battery when the internal temperature is too cold.
However, according to the prior art, the battery is merely cooled by the air suctioned from the interior of the vehicle, therefore, there is currently no method or device for heating these modules in the winter when the battery temperature may become too cold.
Further, the temperature of the air in the interior of the vehicle is not reliable because it can be affected by several variables, such as operating an air conditioner, the number of passengers, an open window or door, the outside temperature, etc. Thus, there is no guarantee that the air provided to the battery is at the proper temperature to effectively cool the battery. That is, the temperature of the indoor air may be too hot or to cool to appropriately cool or heat the battery, thus causing the battery to be overheated or operated inefficiently.
Furthermore, when batteries are operated below a certain temperature (i.e., 0° C.), the voltage supplied from the battery cell decreases. As a result, it may become impossible to supply power the required to the vehicle to start the vehicle. Furthermore, under a low-temperature conditions, the prior art is problematic in that the battery does not charged smoothly. Thus, in order to ensure the performance of the battery, a system for optimizing the temperature of the cell through heating and cooling is essential, and a more reliable control method and a device therefore is required compared to the conventional air conditioning using indoor air.
The description provided above as a related art of the present invention is just for helping understanding the background of the present invention and should not be construed as being included in the related art known by those skilled in the art.